Shares in the credit protection firm CPP sank a further 14% to 129p yesterday after its contract to manage Barclaycard's credit card activation line was cancelled.

The company's shares stood at 280p on March 28 before news of a Financial Services Authority investigation into "failings in sales calls" at the York-based FTSE 250 company saw its value halved. Yesterday's share slump was on fears that the latest move could lead to more of CPP's 200 business partners cancelling contracts.

But the chief executive, Eric Woolley, who brought the 30-year-old company to the stock market last summer, denied that Barclaycard's move had anything to do with the FSA investigation.

"The announcement needs to be put into context," he said. "Barclaycard wishes to review its 'call to confirm' channel. It's not directly related to our announcement two weeks ago."

A spokesperson for Barclays said: "We regularly review our processes including the way we issue replacement cards to our cardholders. We're investigating new ways of establishing safe receipt, where that's appropriate, while giving our customers the opportunity to learn more about our products and some of their newer capabilities."